To provide a hybrid gas turbine engine and high efficient propulsion unit which can be utilized for the next generation power and an ultra low fuel consumption vehicle.

In this hybrid gas turbine engine and propulsion unit, the hybrid gas turbine engine comprises a primary power system 12 and a secondary power system 14, and an accumulator type exhaust heat recovery evaporator 30 is arranged in the secondary power system 14 so as to produce high pressure operational fluid from a low boiling organic solvent, so that an expansion turbine 32 in the secondary power system 14 is driven. The primary power system 12 is intermittently driven by a control device 58 so that the accumulator type exhaust heat recovery evaporator 30 is controlled to be set within a desired operating temperature range. Thus, low fuel consumption and high efficiency can be realized.